The type of GnRH analogue used during controlled ovarian stimulation influences early embryo developmental kinetics: a time-lapse study

OBJECTIVE: To explore if the GnRH analogue used for controlled ovarian stimulation (COS) and the ovulation triggering factor (GnRH agonist + hCG triggering versus GnRH antagonist + GnRH agonist triggering) affect embryo development and kinetics.STUDY DESIGN: In a retrospective cohort study in the Instituto Valenciano de Infertilidad (IVI) Alicante and the Instituto Universitario-IVI Valencia, Spain, 2817 embryos deriving from 400 couples undergoing oocyte donation were analysed. After controlled ovarian stimulation and IVF/intracytoplamic sperm injection, the timing of embryonic cleavages was assessed by a video time-lapse system. The results were analysed using Student's t test for compari…